<s>
In	O
software	O
development	O
,	O
distcc	B-Device
is	O
a	O
tool	O
for	O
speeding	O
up	O
compilation	B-Language
of	O
source	O
code	O
by	O
using	O
distributed	B-Architecture
computing	I-Architecture
over	O
a	O
computer	B-Architecture
network	I-Architecture
.	O
</s>
<s>
With	O
the	O
right	O
configuration	O
,	O
distcc	B-Device
can	O
dramatically	O
reduce	O
a	O
project	O
's	O
compilation	B-Language
time	O
.	O
</s>
<s>
It	O
is	O
designed	O
to	O
work	O
with	O
the	O
C	B-Language
programming	I-Language
language	I-Language
(	O
and	O
its	O
derivatives	O
like	O
C++	B-Language
and	O
Objective-C	B-Language
)	O
and	O
to	O
use	O
GCC	B-Application
as	O
its	O
backend	O
,	O
though	O
it	O
provides	O
varying	O
degrees	O
of	O
compatibility	O
with	O
the	O
Intel	B-Language
C++	I-Language
Compiler	I-Language
and	O
Sun	O
Microsystems	O
 '	O
Sun	B-Application
Studio	I-Application
Compiler	I-Application
Suite	I-Application
.	O
</s>
<s>
Distributed	O
under	O
the	O
terms	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
,	O
distcc	B-Device
is	O
free	B-Application
software	I-Application
.	O
</s>
<s>
distcc	B-Device
is	O
designed	O
to	O
speed	O
up	O
compilation	B-Language
by	O
taking	O
advantage	O
of	O
unused	O
processing	O
power	O
on	O
other	O
computers	O
.	O
</s>
<s>
A	O
machine	O
with	O
distcc	B-Device
installed	O
can	O
send	O
code	O
to	O
be	O
compiled	B-Language
across	O
the	O
network	O
to	O
a	O
computer	O
which	O
has	O
the	O
distccd	O
daemon	B-Operating_System
and	O
a	O
compatible	O
compiler	B-Language
installed	O
.	O
</s>
<s>
distcc	B-Device
works	O
as	O
an	O
agent	O
for	O
the	O
compiler	B-Language
.	O
</s>
<s>
A	O
distcc	B-Device
daemon	B-Operating_System
has	O
to	O
run	O
on	O
each	O
of	O
the	O
participating	O
machines	O
.	O
</s>
<s>
The	O
originating	O
machine	O
invokes	O
a	O
preprocessor	B-General_Concept
to	O
handle	O
header	O
files	O
,	O
preprocessing	O
directives	O
(	O
such	O
as	O
#ifdef	O
)	O
and	O
the	O
source	O
files	O
and	O
sends	O
the	O
preprocessed	B-Language
source	I-Language
to	O
other	O
machines	O
over	O
the	O
network	O
via	O
TCP	B-Protocol
either	O
unencrypted	O
or	O
using	O
SSH	B-Protocol
.	O
</s>
<s>
Remote	O
machines	O
compile	B-Language
those	O
source	O
files	O
without	O
any	O
local	O
dependencies	O
(	O
such	O
as	O
libraries	O
,	O
header	O
files	O
or	O
macro	O
definitions	O
)	O
to	O
object	O
files	O
and	O
send	O
them	O
back	O
to	O
the	O
originator	O
for	O
further	O
compilation	B-Language
.	O
</s>
<s>
distcc	B-Device
version	O
3	O
supports	O
a	O
mode	O
(	O
called	O
pump	O
mode	O
)	O
in	O
which	O
included	O
header	O
files	O
are	O
sent	O
to	O
the	O
remote	O
machines	O
,	O
</s>
<s>
distcc	B-Device
was	O
an	O
option	O
for	O
distributed	O
builds	O
in	O
versions	O
of	O
Apple	O
's	O
Xcode	B-Operating_System
development	O
suite	O
prior	O
to	O
4.3	O
,	O
but	O
has	O
been	O
removed	O
.	O
</s>
<s>
Goma	O
is	O
a	O
similar	O
tool	O
made	O
by	O
Google	O
to	O
replace	O
distcc	B-Device
&	O
ccache	B-Application
in	O
compiling	B-Language
chromium	O
.	O
</s>
<s>
ccache	B-Application
is	O
another	O
tool	O
aimed	O
to	O
reduce	O
the	O
compilation	B-Language
time	O
by	O
caching	B-General_Concept
the	O
output	O
from	O
the	O
same	O
input	O
source	O
files	O
.	O
</s>
<s>
ccache	B-Application
can	O
also	O
use	O
distcc	B-Device
as	O
its	O
backend	O
,	O
providing	O
distributed	O
compiling	B-Language
if	O
it	O
is	O
not	O
already	O
cached	O
by	O
using	O
the	O
CCACHE_PREFIX	O
environment	O
variable	O
.	O
</s>
<s>
icecream	O
was	O
created	O
by	O
SUSE	O
based	O
on	O
distcc	B-Device
.	O
</s>
<s>
Like	O
distcc	B-Device
,	O
icecream	O
takes	O
compile	B-Language
jobs	O
from	O
a	O
build	O
and	O
distributes	O
it	O
among	O
remote	O
machines	O
allowing	O
a	O
parallel	O
build	O
.	O
</s>
<s>
But	O
unlike	O
distcc	B-Device
,	O
icecream	O
uses	O
a	O
central	O
server	O
that	O
dynamically	O
schedules	O
the	O
compile	B-Language
jobs	O
to	O
the	O
fastest	O
free	O
server	O
.	O
</s>
